High-strength and low-hardness ferritic nodular cast iron roll ring and manufacturing method thereof

Abstract

The invention discloses a high-strength low-hardness ferritic nodular cast iron roller ring and a manufacturing method thereof. The roller ring comprises the following chemical components: 3.00-3.10 percent of C, 1.90-2.10 percent of Si, 0.50-0.60 percent of Mn, at most 0.10 percent of Cr, 2.00-2.10 percent of Ni, 0.60-0.70 percent of Mo, at most 0.08 percent of P, at most 0.03 percent of S, 0.04-0.06 percent of Mg and the rest of Fe. The high-strength low-hardness ferritic nodular cast iron roller ring can be strongly extruded for a long term at high temperature so not to be cracked and has good abrasive resistance, extruding toughness and thermal fatigue resistance. The on-machine operation time is prolonged, and the service life of the roller ring is prolonged. Compared with the traditional roller ring, the production cost can be reduced by 22 percent, and the rolling quantity is improved by more than 80 percent.

Description

technical field [0001] The invention relates to a high-strength and low-hardness ferrite nodular cast iron roller ring and a manufacturing method thereof. Background technique [0002] With the high rigidity and high strength seamless steel pipes used in large medium pressure boilers, high pressure boilers, high pressure fertilizer equipment, structural pipes, fluid conveying, petrochemical, oil and gas drilling, gas cylinders, military industry and other equipment and departments, a higher update is proposed. requirements, but for the roll rings used in piercing machines for rolling such seamless steel pipes with superior comprehensive performance, if the roll ring hardness is too high, it is easy to crack and chip when operating in a long-term high temperature and extrusion environment, affecting work efficiency. At present, AS50Mn alloy steel and pearlitic ductile iron are used for seamless steel pipe piercing machines. The former is prone to fatigue cracks due to its lo...

AI Technical Summary

Problems solved by technology

[0002] With the high rigidity and high strength seamless steel pipes used in large medium pressure boilers, high pressure boilers, high pressure fertilizer equipment, structural pipes, fluid conveying, petrochemical, oil and gas drilling, gas cylinders, military industry and other equipment and departments, a higher update is proposed. requirements, but for the roll rings used in piercing machines for rolling such seamless steel pipes with superior comprehensive performance, if the roll ring hardness is too high, it is easy to crack and chip when operating in a long-term high temperature and extrusion environment, affecting work efficiency

At present, AS50Mn alloy steel and pearlitic ductile iron are used for seamless steel pipe piercing machines. The former is prone to fatigue cracks due to its low carbon content and poor wear resistance. The latter has better wear resistance and is also used at high temperatures for a long time Extrusion service in the state, the roll ring is more susceptible to heat, twisting pressure and stress, destroys the matrix structure of the roll ring itself, and has a high factor of thermal fatigue cracks. Both of them have the problem of insufficient use of the roll ring and early retirement. , thus causing the steel pipe production cost to run at a high level for a long time, affecting the benefit and efficiency of the enterprise